The present invention relates generally to venetian blinds of the vertical louver type, and more particularly to a novel operating mechanism for selectively traversing and rotating the louvers and which insures that the louvers are in open louver positions prior to traverse of the louvers from a closed blind to an open blind condition.
Venetian blinds of the vertical louver type employing an elongated guide track or headrail which supports a plurality of louver carriers movable along the guide track and supporting louvers in generally vertical orientation are generally known. Such vertical louver blinds include a louver control mechanism which enables selective traverse of the louver carriers between open blind and closed blind conditions, and facilitates rotation of the louvers about their longitudinal axes between open louver positions lying in planes substantially transverse to the longitudinal axis of the guide track, and closed louver positions wherein the louvers lie in planes substantially parallel to a vertical plane containing the longitudinal axis of the track, whereby to enable selective control of the amount of light passing through the blind.
A preferred operating mode for vertical louver blinds is to rotate the vertical louvers to their open louver positions prior to traversing the louvers from closed blind to open blind conditions. If the louver carriers are caused to traverse the guide track toward an open blind condition while the louvers are in their closed positions lying in planes substantially parallel to a vertical plane containing the longitudinal axis of the guide track, the louvers may jam and cause damage to the control mechanism and/or to the louvers themselves. Such jamming and louver damage only occurs when the louvers are being traversed to their open blind condition wherein the louvers are disposed at opposite ends of the guide track, in the case of a split blind, or at one end of the guide track in the case of a single panel blind. Accordingly, should an operator fail to rotate the louvers to their open louver positions prior to causing the louvers to traverse the guide track toward an open blind condition, substantial damage may be caused to the louvers as well as to the control mechanism.
Attempts have been made to overcome the aforedescribed problem by provding vertical louver control or operating mechanisms which cause the louvers to be first moved to their open louver positions transverse to the longitudinal axis of the associated guide track prior to traversing the louvers from closed blind to open blind conditions. See, for example, U.S. Pat. Nos. 2,898,956, 3,789,905, and 3,878,877. The vertical louver control mechanisms disclosed in these patents are relatively complex, thus being expensive to manufacture as well as leading to increased servicing costs in the event of malfunction.